Apparatus and method for marking a surface



Nov. 22, 1966 R. w. WILSON ETAL 3,286,605

APPARATUS AND METHOD FOR MARKING A SURFACE 2 Sheets-Sheet 1 Filed Sept.50, 1964 F/GZ INVENTORSv SAMUEL E. WISSINGER RUFUS W. WILSON BY LEONA E.WILSON ,DECEASED ADMINISTRA TRIX BY Hem 0 50045 ATTORNEY Nov. 22, 1966w. WILSON ETAL 3,286,605

I APPARATUS AND METHOD FOR MARKING A SURFACE Filed Sept. 30, 1964 2Sheets-$heet 2 ATTORNEY T M NRE E E E5 VGDW mmM $0M SS1 Mum .W E fl 4 WM2 mm m M M w w m M B KQRL ca 006 United States Patent Oflice 3,286,605Patented Nov. 22, 1966 3,286,605 APPARATUS AND METHOD FOR MARKING ASURFACE Rufus W. Wilson, deceased, late of Huntiugdon, Pa., by Leona E.Wilson, administratrix, Huntingdon, Pa., and Samuel E. Wissinger,Huntingdon, Pa., assignors to Prismo Safety Corporation, Huntingdon,Pa., a corporation of Pennsylvania Filed Sept. 30, 1964, Ser. No.400,602 6 Claims. (Cl. 9444) The present invention relates to surfacecoating apparatus and to a method of applying a coating to a surface.More particularly, the present invention relates to a method andapparatus for applying a liquid coating material to surfaces andsimultaneously applying small particles of solid material into and ontothe coating material.

A particular use of the present invention is in the application ofmarkers to roads and highways. It is generally recognized in the art ofapplying road markers, such as center lines and lane margin lines, forexample, that the use of reflecting elements, such as glass spheres,when mixed with a paint binder, is especially effective in promotingsafety on the highway, particularly since the glass spheres haveauto-collimating characteristics. Due to their auto-collimatingcharacteristics, the small glass spheres are particularly effective inoutlining the traffic lanes during night-time driving.

Prior to the present invention, various techiques have been employed inapplying the road markers. The usual method has been to spray a premixof a paint binder mixed with the small glass spheres. A spray gunthrough which the mixture is sprayed is usually attached to a movablevehicle. The resulting marker is not immediately auto-collimating,because all of the glass spheres are completely embedded in thepigmented binder. The marker becomes auto-collimating after traffic hasworn away the binder which covers the beads. In order to render such amarker immediately auto-collimating, it is customary to drop onadditional glass beads onto the tacky paint binder.

It has been found that when the glass spheres are premixed with thepaint binder and not applied immediately to the surface to be marked,the spheres which are initially suspended in the paint or bindersolution, have a tendency to settle with the pigment to the bottom ofthe premix container, thereby forming a wet concrete-like mass. If themass is allowed to remain undisturbed for even a short period of time,it becomes more solid, with the result being that paint lines, valves,strainers and accessory equipment become clogged.

In order to eliminate the difiiculties associated with the premixingtechnique, it has been found desirable to have the paint binder sprayedonto the road surface to effect the desired marker and simultaneouslytherewith to apply the glass spheres from a separate source. Theapparatus as disclosed in Patent No. 2,821,890 includes a spray nozzlefor spraying the paint binder directly onto the road surface incombination with a first spray nozzle for spraying glass spheresdirectly into the paint binder stream. Thus, before the paint spray hasreached the surface to be marked, it has'become premixed with the glassspheres. A second spray nozzle is provided immediately after the paintspray nozzle for spraying spheres onto the upper surface of the paintbinder While it is still tacky to effect a top or flash coat of spheresthereby providing for immediate reflectivity of the marker. The presentinvention is an improvement over the apparatus and process described inPatent No. 2,821,890.

It is an object of the present invention to provide means for applying acoating material to a surface and simultaneously applying therewith astream of small particles from a single independent source to apply theparticles both into the stream of coating material and likewise onto thesurface thereof.

It is a further object of the invention to provide a method of applyinga coating material wherein a transparent binder material is applied tothe surface to be coated while simultaneously applying a stream ofparticles into and onto the coating formed.

Other objects and the nature and advantages of the instant inventionwill be apparent from the following description taken in conjunctionwith the accompanying drawings, wherein:

FIG. 1 is a diagrammatic illustration of the apparatus embodied in thepresent invention;

FIG. 2 is a sectional view of the marker as applied by the apparatusembodied in the present invention;

FIG. 3 is a sectional view of a modified form of marker;

FIG. 4 shows in partial section a gun and deflector for the glass beadsin accordance with the present invention; and

FIG. 5 is a side view of the deflector of FIG. 4.

Generally, the present invention relates to surface coating methods andapparatus for applying a coating to a surface and applyingsimultaneously therewith a stream of small particles which is appliedboth into the coating stream and onto the film of coating which has beenapplied onto the surface to be coated. A preferred application of thepresent invention is in marking a road surface or the like with trafficlines. The road marking apparatus embodied herein is adapted to becarried by a moving vehicle generally of the self-propelled type, andincludes a spray gun that is located a predetermined distance from theroad surface and is adapted to spray a paint binder thereon of a givenwidth to effect a traffic lane stripe. Tiny glass spheres are adapted tobe ejected in a continuous stream into the paint binder stream through asecond spray gun which is provided with a deflector thereon which is sopositioned rearwardly of the first spray gun so that the spheres aresimultaneously ejected into the paint binder stream and also onto thefreshly applied marker as a top or flash coat of spheres.

Referring now to the drawings and particularly to FIG. 1, the apparatusembodied herein is diagrammatically illustrated and includes a spray gunindicated at 10. The spray gun 10 is of the general type employed fortraflic lane marking and includes a nozzle 12 through which an atomizedspray of paint binder mist is ejected under the motive force ofcompressed air. The spray gun 10 and the conventional equipmentassociated therewith, such as the compressor and prime mover, areadapted to be mounted on a vehicle preferably of the self-propelledtype, the vehicle also carrying a supply of paint binder, not shown, aswell as a tank 14 for the glass spheres and a spray gun 16 for sprayingthe glass spheres. The spray gun 10 is connected to the supply of paintbinder, the paint binder being ejected from the nozzle 12 in a fanshaped stream 18 onto a surface 20 to define a marker 22 ofpredetermined width. The width of the marker is determined by the heightof the spray gun 10 from the surface 20 and the angle of the spray gunalthough it is usually maintained in a vertical direction.

As shown in FIG. 1, the spray gun 16 for the glass spheres is angularlypositioned directly adjacent the spray gun 10 and is located rearwardlythereof with respect to the direction of travel of the vehicle, thedirection of travel being indicated by the arrow shown above the spraygun 10in FIG. 1. The axis of spray gun 16 is seen to intersect thesurface 20 at a point which is located slightly forwardly of the pointof application of stream 18 thereon. The spray gun 16 is shown in detailin FIG. 4 and is connected by a line 24 to the hopper 14 which ismaintained 3 pressurized by air under pressure. Air pressure to the tank14 should be approximately 5060 lbs. and this is set and controlled by apressure regulator valve 26. The air for pressurizing enters through afilter 28 and line 30 passing through stop cock 32, pressure indicator34 and safety valve 36, and then into the tank 14. An exhaust valve 38is provided for relieving the pressure from the tank. As shown, the tankis provided with a lid 40 which is clamped thereon. When the airpressure is applied on the glass tank 14, glass spheres are forcedthrough the lines to the glass spray gun 16.

The glass spray gun 16 is shown in more detail in FIG. 4. In general, itis air operated with a spring tension closing action so that when air tothe gun is removed, a needletype plunger shuts off the glass supplyunder coil spring tension. The glass gun comprises an operating cylinder42 at the top thereof which houses the coil spring 44 operating on apiston 46. A needle-stem 48 is attached to the piston 46 and has a valve50 at the lower end thereof. A fluid nozzle 52 is located immediatelybelow the valve 50. Immediately below the fluid nozzle 52 is thedeflector 54. Thus, when air pressure is admitted to the line 56, thepiston 46 rises carrying the valve 50 from its seat and therebypermitting the glass spheres to flow through line 24, nozzle 52 andthence through the deflector 54. The deflector 54 is preferably made ofbrass and gives a controlled glass stream pattern, as shown in FIG. 1,that partially mixes with the paint stream 18 before it reaches thesurface 20 and partially reaches the layer of paint which has alreadybeen deposited on the surface 20. Thus, the glass spheres which contactthe stream of paint 18 issuing from the spray gun 20 are premixedtherewith and are embedded in the line which is deposited. The glassspheres which reach the marker after it has been de posited becomepartially embedded in the upper surface thereof.

As shown, the deflector 54 is curved downwardly to confine the stream ofparticles in a fan shaped controlled pattern similar to the fan shapedstream previously described as issuing from nozzle 12.

The glass spheres which are normally used for road marking purposes aregraded by sieve analysis and are required to conform to the followinggradation:

U.S. Standard Sieve Minimum, Percent Maximum, Percent Retained:

Passing With this gradation in size of the spheres, it is noted that thelarger, heavier spheres will be sprayed somewhat further than thelighter spheres. Thus, the spheres which are heavier ranging from 20 to50 US. standard sieve size, will tend to reach the spray 18 and tobecome embedded therein; whereas the lighter, smaller diameter spheresof 80 to 200 US. standard sieve size will not travel as far from theglass spray gun 16 and will become deposited on the top of the wet paintline. Thus, the finished marker, as shown in FIG. 2 will have the largerglass spheres 60 completely embedded in the paint binder 62 whereas thesmaller spheres 64 will be partially embedded in the upper surface ofthe line, thereby yielding an instantly reflective layer of reflectivespheres on a substantially premixed paint line. Thus, through abrasion,those spheres that are completely embedded are gradually uncoveredthrough abrasion of traflic, thereby exposing their reflective qualitiesas the line is worn down.

As a modified method of operation, the material sprayed through the gun12 may be a transparent binder material and the particles which aresprayed through the gun 16 may be a mixture of regular road glassspheres and colored resin-coated glass spheres. Thus, as shown in FIG.3, a marker would be produced wherein the coated glass spheres 66 areincluded in the transparent binder 68 along with the uncoated glassspheres 70. The coated glass spheres may be coated with a resin coatingOlf any desired color and will thereby add the desired daylight color tothe line being sprayed without the use of the normal pigments. If thecoated glass spheres are somewhat larger than the uncoated glassspheres, then the glass spheres which are coated will become completelyembedded in the transparent binder layer and the uncoated smaller lglassspheres will form the partially embedded top coating so that the linebeneath the top coating of spheres will have the color of the coatedglass spheres.

Thus, it is seen for the first time it is possible to obtain animmediately reflective glass coated marker which also contains glassbeads which are completely embedded in the marker without the use of apremix and without the use of two glass guns as heretofore proposed. Inaccordance with the present invention a single glass gun in combinationwith the deflector illustrated will simultaneously act to premix glassbeads within the spray and to top the formed marker while it is stilltacky with glass spheres. As illustrated, the deflector 54, is curved atits lower portion and is commonly referred to as a water knife. Thisdeflector acts to enlarge the spray pattern of the glass spheres over alarger area so that it will contact both the spray 18 from the gun 12 aswell as the ground 20 onto which the marker is being sprayed.

The binder which is sprayed through the spray gun 10 may be of any typeof low viscosity, fast evaporating pigmented or non-pigmented material,such as alkyds, modified alkyds, vinyls and the like, which has beenmixed with a solvent to a sprayable consistency to yield a fast-dryingpaint.

The idea of introducing the colored coated glass spheres into a clear,transparent binder at the gun at the time of application to a surfaceeliminates the necessity of separate tanks for each color marker whichit is desired to be sprayed. Thus, a single tank containing atransparent binder can be utilized and the various colors of glassspheres can be utilized in the sphere tank, thus making the single pieceof equipment available for spraying various colored lines without thenecessity of cleaning and washing out the paint tank before changingcolor. It should also be noted that in addition to spraying the glassspheres and color coated glass spheres that the same apparatus can beutilized for spraying normal pigments into a transparent binder to yieldconventional pigmented binders. This has the advantage of using anon-pigmented binder which does not settle out nor clog the lines andequipment upon sitting.

It will be obvious to those skilled in the art that various changes maybe made without departing from the spirit of the invention and thereforethe invention is not limited to what is shown in the drawings anddescribed in the specification but only as indicated in the appendedclaims.

What is claimed is:

1. Apparatus for applying a coating to a surface com prising first meansfor ejecting a stream of coating material onto said surface, the axis ofsaid ejecting means being substantially perpendicular to said surface,and a second ejecting means located rearwardly of said first ejectingmeans with respect to the direction of travel thereof for ejecting astream of particles, the axis of said second ejecting means being at anangle to the axis of said first ejecting means, the axis of said ejectedstream of particles intersecting said surface slightly forwardly of thepoint of application of said first stream whereby a portion of thestream of particles is intimately mixed with said stream of coatingmaterial prior to the application thereof to said surface and a portionof the stream of particles falls onto said coating after applicationthereof to said surface.

2. Apparatus as set forth in claim 1 wherein a deflector is located atthe end of said second ejecting means for effecting a fan-shaped sprayof said particles.

3. Apparatus adapted to be attached to a moving vehicle for applying acoating to a surface comprising a first nozzle for ejecting a continuousstream of coating material under pressure toward said surface, and asecond nozzle located rearw-a-rdly of said first nozzle with respect tothe direction of travel thereof for ejecting a stream of particles, theaxis of said ejected stream of particles intersecting said surfaceslightly forwardly of the point of application of said first streamwhereby a portion of the stream of particles is intimately mixed withsaid stream of coating material prior to the application thereof to saidsurface and a portion of the stream of particles falls onto said coatingafter application thereof to said surface.

4. Apparatus as set forth in claim 3 wherein a deflector is located atthe end of said second nozzle for controlling the pattern of said streamand directing it downwardly.

5. A method of applying an immediately reflective marker onto a roadsurface comprising the steps of spraying a fan-shaped stream of paintbinder substantially perpendicularly onto said road surface from amoving external source, and simultaneously ejecting a stream of dryglassspheres in an atomized fan-shaped spray rearwardly of said streamof binder, said stream of spheres being ejected at an angle to the axisof said stream of binder so as to intersect said road surface slightlyforwardly of the point of application of said stream of binder whereby aportion of the stream of spheres is intimately becomes partiallyembedded therein as a top coating for immediate reflectivity of saidmarker.

6. A method of applying an immediately reflective marker onto a roadsurface comprising the steps of spraying a fan-shaped stream oftransparent binder substantially perpendicularly onto said road surfacefrom a moving external source and simultaneously ejecting a stream ofdry glass spheres in an atomized fan-shaped spray rearwardly of saidstream otf binder, said stream of spheres being ejected at an angle tothe axis of said stream of binder so as to intersect said road surfaceslightly forwardly of the point of application of said stream of binderwhereby a portion of the stream of spheres is intimately mixed with saidstream of binder prior to the application thereof to said road surfaceand a portion of the stream of particles falls onto said marker afterapplication thereof to said road surface while it is still tacky, atleast a portion of said ejected glass spheres being coated with anopaque colored coating whereby said colored coated spheres act as thecolored pigment in said marker and the uncoated glass spheres act asretroreflective elements for immediate reflectivity of said marker.

References Cited by the Examiner UNITED STATES PATENTS 2,201,534 5/1940Hallenbeck 9444 2,833,542 5/1958 Martin 94-44 X 3,057,273 10/ 1962Wilson 9444 FOREIGN PATENTS 396,625 1/ 1933 Great Britain.

JACOB L. NACKENOFF, Primary Examiner.

1. APPARATUS FOR APPLYING A COATING TO A SURFACE COMPRISING FIRST MEANSFOR EJECTING A STREAM OF COATING MATERIAL ONTO SAID SURFACE, THE AXIS OFSAID EJECTING MEANS BEING SUBSTANTIALLY PERPENDICULAR TO SIAD SURFACE,AND A SECOND EJECTING MEANS LOCATED REARWARDLY OF SAID FIRST EJECTINGMEANS WITH RESPECT TO THE DIRECTION OF TRAVEL THEREOF FOR EJECTING ASTREAM OF PARTICLES, THE AXIS OF SAID SECOND EJECTING MEANS BEING AT ANANGLE TO THE AXIS OF SAID FIRST EJECTING MEANS, THE AXIS OF SAID EJECTEDSTREAM OF PARTICLES INTERSECTING SAID SURFACE SLIGHTLY FORWARDLY OF THEPOINT OF APPLICATION OF SAID FIRST STREAM WHEREBY A PORTION OF THESTREAM OF PARTICLES IS INTIMATELY MIXED WITH SAID STREAM OF COATINGMATERIAL PRIOR TO THE APPLICATION THEREOF TO SAID SURFACE AND A PORTIONOF THE STREAM OF PARTICLES FALLS ONTO SAID COATING AFTER APPLICATIONTHEREOF TO SAID SURFACE.